Combined strainer and check valve



Sept.- 16, 1930. w; wlsl-lART 1,775,744 I.

COMBINED STRAIFER AND CHECK VALVE Filed Dec. 21, 1925 3 shoatsvsheet 1Sept. 16, 1930. w. WISHART 1,775,744

COMBINED STRAINER AND CHECK VALVE Filed Dec. 21, 1925 2 Shoots-Sheet 2 2if z 5 j 55 Kg u Patented Sept. 16, 1930 UNITED STATES PATENT! orncsWILLIAI WISHART, OI CLINTON, IOWA, ASSIGE'OB T CLIIAZ' ENGINEERING COI-PANY, A CORPORATION OF DELAWARE COMBINED STRAINER AND CHECK VALVEApplication filed December 21, 1925}. Serial No. 76,878.

This invention relates primarily to an improved combmatlon suctionstrainer and check valve construction adapted to be 'used' unit to thecompressor.

It is an object of this invention to rovide a combined suction strainerand chec valv e mounted within the same housing to eliminate the leakageordinarily encountered in pipe joints.

It is also an object of this invention to provide a strainer and checkvalve unit adapted for use in the pipe connecting the expansion coil andcompressor of a refrigerating unit.

It is a further object of this invention to provide ahousing adapted tobe connected in the pipe line between the expansion coll go and thecompressor of a refrigerating unit,

said housing having mounted therein an improved suctlon strainer or oilseparator device through which the expanded refrigerant must pass beforebeing permitted to pass through a check valve also mounted in saidhousing between the strainer and the outlet pipe leading to acompressor.

It is an important ob'ect of this mvention to provide a simplifiestrainer and check valve construction ada ted to be enclosed by a singlehousing whic is connected in the pipe line leading between the exhaustend of an expansion coil and the intake end of a compressor forming partof a refrigerating unit. 1

Other and further important objects of this invention will be apparentfrom the disclosures in the specification and accompanying drawings.

The invention (in the preferred form) is illustrated in the drawings andhereinafter Figure 2 is a vertical detail section taken on line 11-11 ofFigure 1 showing parts in elevation.

Figure 3 is an enlarged vertical detail section of a modified form ofsuction strainer.

As shown on the drawings:

The reference numeral 1 indicates a supporting framework or base forminga part of a refrigerating unit. Secured to the framework 1 by means ofbolts 2 or other suitable means is the apertured base plate 3 which isintegrally formed on the lower end of a housing or casing 4. The housing4 is hollow and is provided with an inner flange or partition ring 5which divides the interior of the housing into a lower intake chaniber 6and an upper outlet chamber 7. The upper portion of the housing 7 isprovided with an outlet passage or opening 8 above the partition 5 andleading outwardly from the upper dischar e chamber 7. Connected to oneside of the lower portion of the housing 4 is an inlet pipe 9, the otherend of which is connected with the exhaust end of an expansion coil of arefrigerating unit to permit the expanded refrigerant from the expansioncoil to flow through the pipe 9 into the lower intake chamber 6 of thehousin 4.

As clear y shown in Figure 2, one wall of the housing 4 is provided witha circular groove 10 around the outlet opening 8 to receive the circularflange 11 which is integrally formed on one side of a mouthpiece or hood12. Secured against the grooved face of the housing 4 to cover theoutlet opening 8 is a flap valve 13, one portion of which is held inposition by means of a retaining screw 14 or other suitable means. Thevalve 13 is adapted to act as a check valve and is positioned within therecess 15 formed by the flanges 11 of the mouthpiece 12. The mouthpiece12 is integrally formed on one end of an elbow or pipe 16 the other endof said pipe 16 being connected to communicate with the intake chamberof a compressor 17 forming a part of the-refrigerating unit. The pipe 16is secured to the compressor 17 by means of bolts 18 or other suitablemeans.

The upper end of the housing 4 is open and is adapted to be closed bymeans of a top plate or cover 19 which is rigidly secured to the top ofthe housing -by means of bolts 20 or other suitable means. The top plateor cover 19 is provided with a central opening 21 which is normallyclosed by means of a threaded plug22. Integrally formed on the innerface of the cover 19 is a hollow sleeve 23 which projects through thehousing outlet chamber 7 and into the upper end of the housing intakechamber 6. Integrally formed on the lower portion of the sleeve 23 is aflange 24 which fits tightly into the housing flange 5 and thusseparates the two chambers 6 and 7. The sleeve 23 is provided with anoutlet opening 25 which communicates with the upper chamber 7 of thehousing 4. The lower end of the sleeve 23 is open and communicates withthe lower housing chamber 6 through a strainer.

The strainer comprises a cylindrical steel shell 26 the upper end ofwhich is secured to and fits tightl around the lower end of the sleeve23. ounted within the strainer shell 26-at s nod intervals are aplurality of screens 27 dividing the shell into a plurality of chambersor compartments, each of which is filled with a packing 28.

By referring to Figure-2 it will be noted that the housing 4 which isconnected between the exhaust end of a refrigerating unit expansion coiland the intake end of a compressor is constructed to contain both asuction strainer and a check valve mechanism, thus affording aconstruction adapted to eliminate leakage, which is usually encounteredwhen a plurality of pipe joints are provided in the refrigerantcirculating system of a refrigerating unit.

Figure 3 covers aniodified form of a strainer unit adapted for use inthe refrigerant circulating system of a refrigerating unit. The modifiedform of the device comprises a c lindrical casing or housin 29, theupper and lower ends of which are closed by means of grooved closureplates or heads 30. The heads 30 are apertured and connected by means ofconnecting bolts 31. The bolts 31 act to securely hold the heads 30engaged against the ends of the housing 29. Projected into an opening inthe lower portion of the housing 29 is one end of a refrigerant intakepipe 32, the other end of which projects into a manifold 33. Themanifold 33 is connected by means of a pipe to the exhaust end of anexpansion coil of a refrigerating unit. Projecting into an aperture inthe upper portion of the housing 29 is one end of a pipe 34, the otherend of which is connected with the intake end of a compressor forming apart of a refrigerating unit.

The central portion of the inner face of the upper head 30 is providedwith a recess 35 in which the upper end of a compound or multiplecylindrical screen 36 is seated. The screen 36 comprises a plurality ofconcentric cylindrical screens secured together to provide a sleevewhich projects downwardly into the upper portion of the housing 29' to apoint below the opening in which the pipe 34 is engaged. Projecting intothe lower end of the multiple screen sleeve 36 is the upper end of asteel cylindrical shell 37. Securely mounted Within the shell 37 atspaced intervals are a plurality of sets of screen plates 38, saidgroups of screen plates separating the interior of the shell 37 into aplurality of compartments each of which is filled with a packing 39.Rigidly secured around the upper portion of the shell 37 below the lowerend of the screen sleeve 36 are a pair of felt retaining rings 40separated by a felt packing 41. The felt retain ing rings 40 and thepacking 41 separate the interior of the housing 29 into a lower intakechamber 42 and an upper outlet chamber 43.

The operation is as follows:

In a refrigerating unit the refrigerant, after entering the expansioncoil, is adapted to be discharged through the exhaust end of theexpansion coil and is permitted to flow back to the compressor throughthe pipe 9. Connected between the pipe 9 and the elbow pipe 16 is theimproved combination strainer and check valve mechanism. The expandedrefrigerant from the expansion coil flowing;

through the pipe 9 enters the lower portion of the housing 4 and flowsinto the lower chamber 6 around the strainer mechanism within saidchamber. The refrigerant is adapted to be drawn by means of suctionupwardly.

through the screens 27 and through the packing 28 separating saidscreens to be purified before entering the chamber within the sleeve 23.The impurities in the refrigerant having been removed by the improvedstrainer, said refrigerant, is permitted to flow from the interior ofthe chamber outwardly through the discharge port or opening 25 into theupper chamber 7 of the housing 4 which upper chamber 7,

provides for the accumulation of purified refrigerant to insure uniformoutflow past the valve 13 during suction of the compressor. By thuspermitting of the accumulation of a supply or head of refrigerantbetween the.

strainer and the outlet valve, heavy suction upon the strainer itself isavoided and greater uniformity in the supply of refrigerant to thecompressor is insured. From the chamber 7 the purified refrigerant isadapted to escape through the discharge port 8 past the flap valve 13which is opened by the flow of the refrigerant and by the suction actionproduced in the elbow pipe 16. After passing the open valve 13 thepurified refrigerant enters the mouthpiece 12 and flows through the elbow pipe 16 into the receiving chamber of the compressor 17. It willthus be seen that the improved invention provides but a single housingfor both the suction strainer'and the.

. sleeve in said housing divi check valve mechanism thereby eliminatingleaks which often occur when pipe joints are extensively used.

In the modified form of the device illustrated in Figure 3 the expandedrefrigerant from the exhaust end of the expansion coil of arefrigerating unit is adapted to flow through the manifold 33 and thepipe 32 into the lower chamber 42 of the housing 29. The refrigerant isthen permitted to be drawn upwardly through the sets of screens 38 andthrough the packing 39 separating said screens so that the impurities inthe expanded refrigerant are removed, permitting the reand communicatingwith said port, a shell within said housin connected with sa d sleeve, aplurality 0% spaced screens in said shell, packing separatlng saidscreens, an elbow pipe connected to said housing, and a control valve insaid elbow pipe and mounted on said housing for governing the flow of arefrigerant through said exhaust port.

In testimony whereof I have hereunto subscribed my name.

1 WILLIAM WISHART.

fined or screened refrigerant to enter the a chamber provided by thecylindrical sleeve screen 36. From the screen 36 the refrigerant ispermitted to be drawn through the walls of the sleeve to enter theuperhousing chamber 43 from which chamb er the purlfied refrigerant ispermitted to flow through the pipe 34 back mto the compressor of arefrigerating unit.

I am aware that many changes may be made and numerous details ofconstruction may be varied through a wide range without departing fromthe principles of this invention, and I therefore do not purposelimiting the patent granted hereon, otherwise than necessitated y theprior art.

I claim as my invention:

1. The combination with a housing adapted to be connected between theexpansion coil and compressor of a refri eratmg unit, a (fing the housmginto upper and lower chambers, a shell in said housing connected to saidsleeve and extending downwardly therefrom into said lower chamber, aplurality of screens in said. shell, and packing in said shell betweensaid screens, said upper chamber rovided for carrying a head of purifiedre rigerant.

2. A strainer and check valve mechanism comprising a housing having adischarge port therein an apertured sleeve projecting 1nto said housingto divide the interior thereof into lower and upper chambers, a shellsecured to said sleeve and projecting into the lower chamber, said upperchamber serving to permit a head of puri ed refri erant to be carried inthe upper end of said housing, a plurality of space screens in saidshell, packm in said shell between said screens, and a va ve on saidhousing for controllin the flow of the refrigerant through saiddischarge port. I

3. A strainer and check valve mechanism comprising a chambered housin arefrigerant mlet pipe connected to said housing to communicate with oneof the chambers thereof, a refrigerant head in another chamber of saldhousing, a discharge port in said hous ing communicating with saidrefrigerant head carrying chamber of said housing, an apertured'sleeveprojecting into the housing

